Cut-out



May 31,1927. 1,630,358

M. J. SANDIN CUT-OUT Filed April 1. 1922 i azazzzwzkaamzwgggg WITNESSES:

ATTORNEY Patented May 31, 1921?.

UNITED STATES PATENT OQFFICE.

' 'maums a. samam, or WILKINSBUBG, PENNSYLVANIA, AssieNon 'rowns'rmenoUsEELEc'rRIo & MANUFACTURING .vmm.

Application filed April 1,

" My invention relates to cut-out mechanism and articularly tothermal-responsive cirwit-interrupting mechanism for protecting electricapparatus from excessive current.

One object of my invention is to provide a cut-out mechanism that may bereset repeatedly and that may be installed 1n a casingfor receptaclesimilar in shape and dimensions to a standard cartridge fuse of equalcapacity and which may be mounted in standard fuse clips or jaws andsubstituted for standard fuses.

Another object of my invention is to provide a cut-out device, havingthe above characteristics, that will open the circuit underpredetermined overload conditions and wishin a predetermined time andwherein means are provided for so regulating the thermalresponsiveelement thereof that it will respond to difierent predetermined currentconditions.

. Another object of my invention is to provide a thermal cut-out thatmay be manually closed or reset, or manually released or 7 opened, andwhich is responsive to predetermined current conditions.

Another object of my invention is to provide a cut-out device wherein abarrier is interposed between one of the contact members of theconductors and the actuating mechanism therefor for preventing damagetothe latter when the circuit is interrupted.

Another object of my invention is to provide a cut-out mechanism that issimple and inexpensive to manufacture. i

These and other objects, that will be made apparent throughout thefurther descriptionof my invention, are attained by means of theapparatus hereinafter described, and illustrated in the accompanyingdrawings, wherein:

Figure 1 is a longitudinal section through a cut-out or switch mechanismembodying features of my invention;

Fi 2 is a view similar to Fig. 1, showing certain elements ininoperative position;

Fig. 3 is a transverse sectional view taken on the line III-III of Fig.1,

Fig. 4 is a fragmentary longitudinal sec" ,tional view of a modifiedform of cut-out construction, and

Fig. 5 is a view of a portion of a modified form of latch mechanism.

I Referring to the drawings, the put-out. mechanism includes a tubularInsulating cas- GUT- COMPANY, A CORPORATION OF PENNSYL- OUT- 1922.Serial No. 548,659. I

ing 5 having end ferrules 6 and 7 substantially closing the end of thetube or casing. The insulating tube and the ferrules are similar inshape and dimensions to those of cartrldge fuseshaving an equal capacityand, therefore, the casing is adapted to be inserted in standard fuseclips and jaws, it being the purpose of the device, in some cases, totake the place of standard fuses, the advantage of the device over thestandard fuse be- 1ng that, after the circuit is interrupted, due toeither overload or short-circuit conditions in the circuit, it may berepeatedly reset without requiring replacement of any parts thereof.

A conducting rod or contact member 8 is,

element, comprising a heating coil, preferably made of a high-resistancemetal, is embedded in a tubular sheath of heat-absorbinginsulating-material that is enclosed within the metal sleeve 14. One endof the coil 12 is conductively attached to the ferrule 6 and the otherend is conductively connected to the rod 8, as indicated in Fig. 1.

A bimetallic thermal-responsive element 15 is mounted upon the conductor8 and comprises two metal strips that are welded together and havedifferent coefficients of expansion. Variations of the temperature ofthe bimetallic element cause the free end thereof to be moved toward thewalls of the casing 5. The element is placed in close proximity to theheating element 11 and, when heated, serves to move a latch member 16away from the contact member 8.

An insulating rod 17 is slidably mounted in the ferrule 7 forlongitudinal movement and carries, at its inner end, a flexibleconductor 18 having an offset portion 19 that is adapted toautomatically slip into a notch The contact member 18 is conductivelyconnected to the ferrules 7 by means of a flexible conductor 21 that isattached, at one end, to the contact member 18 and, at the other end, tothe ferrule 7. The contact member 18 is normally yieldingly retained inspaced relation to the conductor 8, or in open position, bymeans of ahelical spring 22 that is secured, at one end, to the-inner end of therod 17 'and,--at the other end, to

. member 18. The yoke 24 is provided with inwardly-turned projections 25that engage the inner face of the oll'set portion 19 of the contactmember 18 in such manner that, when the latch 16 is moved toward thewalls of the casing 5, the offset portion 19 of the contact member 18 iswithdrawn from engagement with the notch 20 and the circuit broken byreason of the separation of the contact members. The spring 22 is ofsuch construction that it causes the contact member 18 to be withdrawnfrom the contact member 8 with a snap-action.

In order that the thermal-responsive element 15 may be adjusted torelease the contact member 18 .under different predetermined currentconditions, it is provided with an .adjusting screw 26 having threadedenga ement with the latch member 16. The

en of the screw 26 engages the free end of the bimetallic member 15 and,by turning the screw 26, the position of the latch member 16 relative tothe end of the bimetallic element may be varied. By reason of thisadjustment, the cut-out mechanism .may be made to operate at differenttime intervals with a given current or at equal time intere vals withdifferent currents.

In order to provide convenient means for actuating the latch member 16manually, the latch 16 is provided with a tube 27 that surrounds. theshank of the screw 26 and extends through an opening 28 in thecasing 5.The outer end of the tube is rovided with an insulating handle 29 whichmay be gripped for manually operating and trip mg the latch 16 to causethe circuit to be interrupted. The handle 29 is provided with a centralopening 31 which permits of movement of the screw 26 therein. The headof the screw 26, however, lies beneath the outer face of the handle 29and, consequently, cannot be operated or adjusted, or accidently turned,except by means of a proper tool, such as a screw driver,

The operation of the cut-out is as follows: the casing is placed withinthe fuse-jaw members of the circuit in a manner usual to fuses of thecartridge type, with the handle 29 extending outwardly in an ac sibleposition. The screw 26 is adjusted to release the latch 16 under desiredcurrent conditions. lVhen an overload occurs in the circuit for apredetermined length of time, the heating element 11 transmits heat'tothe bimetallic element which causes outward movement of open positionindicated in Fig. 2 with a snap action. WVhen it is desired to open thecircuit manually, the handle orknob 29 is pulled outwardly and thecontact-member 18 is released by the latch member 16.

Referring to Fig. 4, wherein a modified form of construction isillustrated, it will be seen that the bimetallic element serves as aheating element, thereby eliminating the necessity for an auxiliaryheater, such as is illustrated in Fig. 1. The construction of thecasing, end ferrules and manual-releasing mechanism is identical to thatof the device above described. In the modified form, however, thebimetallic element 15 is directly connected to the end ferrule 6, andthe conductor or contact member 8 is insulated from the ferrule. Thefree end of the bimetallic strip 15 is connected to the contact member 8by means of a flexible conductor 32. In this construction, excess cur--rent, passing through the bimetallic element 15, causes it to be heated.This action causes the free end of the element 15 to move outwardly andto release the offset portion 19 of the contact member 18 from en mentwith the contact member 8 an th circuit to be broken by the openingmovement of the contact member 18.

A more sensitive latchin device is illustrated in Fig.5, wherein t econtact memios ber 18 is provided with a relatively light spring 33 thatengages the notch 20 and retains the contact member in engagement withthe conductor 8. A device of this character releases the contact membersat relatively low current values.

It will be apparent from the foregoing that the construction provides asimple an effective cut out device that may be used where cartrid efuses have heretofore been employed. ile the device is capable ofinterrupting short-circuits, it may be advisable to place a fuse ofgreater ca acity than the cut-out device in series for the purpose ofpreventing injury to the cut-out mecha nism under severe short-circuitconditions.

While I have shown a device as applied to a cartridge fuse of .theferrule type, iti is.

obvious that the device may be designed for use in fuse clips adapted toreceive blades of cartridge fuses having blade terminals.

The device is particularly well adapted for use in motor circuitswherein it is desirable to provide overload protection. The

thermal-responsive elements may be so proportioned that they are notactuated by normal starting currents but will cause the circuit to beopened when an overload has prevailed a predeterminedtime.

While I have describedand illustrated but two embodiments of myinvention, it will be apparent to those skilled in the art that variouschanges, modifications, additions, substitutions and omissions may bemade in the apparatus illustrated without departing from the spirit andscope of my invention, as set forth in the appended claims.

I claim as my invention: 1

1. A cut-out device comprising a tubular insulating casing, terminalmembers mounted on the ends of the casing, relatively movablecontactmembers connected to the terminal members and adapted to conductivelyconnect the terminal members, latching means for securing the contactmembers in engagement, means for separating the concontact membersconnected to the terminal members and adapted to 'conductively connectthe terminal "members, means for separating the contact members in adirection longitudinally of the casing, and a barrier .on one of themembers extending transversely of the casing.

In testimony whereof, I have hereunto subscribed my name this 13th dayof March MAURITS J. 'SANDIN.

